In FreeBSD, the best way to install component is Portinstall. It compile from the latest source, but the cons is it took long time to install, if you are installing Mozilla Firefox, it probably take you 5-6 hours. Not to mention how long does Gnome installation take.
For me, I am using package install, because it’s much much more faster, rather than siting in front the text mode and can’t work on anything. After FreeBSD installation, after cvsup your package, I would recommend you install gnome using pkg_add -r gnome2, Xorg and etc. While you have X-Windows, you can run Portupgrade -arR to upgrade your ports.